Generally, a magnetic tape recording and/or reproducing apparatus, such as a cassette type video tape recorder, draws the magnetic tape out of the cassette and winds the tape at a predetermined angle onto a guide drum positioned outside the cassette and carrying magnetic heads, the apparatus often being provided with a motor for exclusive use to mechanically simplify the tape loading operation. Such video tape recorder has been constructed to directly transfer the rotation of the motor so that a magnetic tape loading member has been moved inreciprocation between a first position where the magnetic tape housed within the cassette can be drawn out therefrom and a second position where the magnetic tape is drawn out from the cassette and wound at the predetermined angle on the guide frame. In order to perform recording/reproducing of the signal with accuracy at the second position, especially between the magnetic tape and the magnetic head, a stop for the magnetic tape loading member is disposed at the second position so that the accuracy of the stop position of the magnetic tape loading member at the second position is improved to determine the winding angle with accuracy and the member is stably fixed. A spring is interposed between the magnetic tape loading member and a drive unit so as to bias the magnetic tape loading member to bring it into press-contact with the stop. In such construction, however, the amount the spring is extended after the abutment of the loading member against the stop depends upon the stop position of rotation of the motor, so that especially when the spring constant is enlarged for increasing the press-contact strength, the force against the stop varies greatly. Also, it has been necessary for stabilization of the member to considerably increase the press-contact strength and the required torque of the motor, which has usually hindered miniaturization of the motor and reduction of power consumption thereof.
Recently, a method useful for achieving low manufacturing cost and light weight has been proposed, which changes the operation of the apparatus by use of the motor for loading the magnetic tape. Such method, for example, is disclosed in U.S. patent application Ser. No. 230,367, now U.S. Pat. No. 4,408,236. In this method, when the magnetic tape loading member is biased and abutted against the stop, the reaction of the biasing force of the spring is loaded on the changing apparatus to cause a large current to flow into the motor and also friction of the parts and wearing of slide parts, e.g., a cam groove and a cam follower in the aforesaid patent application, have remarkably increased, resulting in that the mode changing operation of the apparatus is unstable and the reliability of the apparatus is low.
This method also is usually so constituted that the motor unidirectionally rotates to change the operating mode from a stopping mode to a fast-forward-winding mode and reversely rotates to change the operating mode vice versa, but the motor speed is substantially reduced to gain sufficient power for operation. Therefore, it takes much time to change the operating mode from the fast-forward-winding mode to the stopping mode so that the tape, even when a point near the end is optically detected, can be completely unwound and an excessive tension applied thereto which may damage the tape. Furthermore, such method often uses a cam for the mode changing operation, the cam being limited with respect to the size or pressure angle so that a sufficient stroke is not obtainable for exerting the braking action on reel turntables, thus requiring strict supervision for the accuracy of each part and adjustment during assembly. Recently, the tendency has been for magnetic recording and/or reproducing apparatus to be provided with various functions, such as a quick motion reproduction or slow motion reproduction, but it is difficult to change the operation mode to such functions quickly by rotation of the motor and operation of a brake in response to the mode changing operation, especially because the braking action cannot be switched to the condition of drawing the tape out of the cassette. Hence, a solenoid has usually been used at the sacrifice of the weight and the manufacturing cost.